The present invention relates generally to exhaust systems used in commercial kitchens, and more particularly, to a wash water recirculation unit and system for use in cleaning ventilation system equipment such as ventilators and smoke pollution control units used in commercial kitchens.
Kitchen ventilator hoods have long been provided for the purpose of exhausting steam, smoke and particulates such as grease which are produced in the commercial kitchen environment. It is common to periodically clean such ventilators using a combination of hot water and a cleaning agent by feeding the combined water/cleaning agent internally to the ventilator and thereafter disposing of the water/cleaning agent by feeding it to a drain. Other types of ventilation equipment such as smoke pollution control units are also periodically cleaned in the same manner. In large commercial kitchens the cost incurred as a result water and heat used for such cleaning operations can be significant.
As used herein the term xe2x80x9cventilation equipmentxe2x80x9d is intended to broadly encompass ventilators themselves as well as any other type of device or structure positioned along the exhaust path including, but not limited to, smoke pollution control units, grease exhaust duct work, grease exhaust duct sumps, and grease exhaust fans.
In one aspect, a method of cleaning ventilation equipment in commercial kitchens involves (a) providing a tank for holding a supply of heated wash liquid; (b) maintaining a temperature of the heated wash liquid in the tank at or above a threshold minimum temperature; (c) establishing a plurality of ventilation equipment cleaning stations; (d) performing the following steps for each ventilation equipment cleaning station: (i) delivering heated wash liquid from the tank to the ventilation equipment cleaning station; (ii) returning the heated wash liquid from the ventilation equipment cleaning station to the tank; wherein step (d) is performed for each ventilation equipment cleaning station in a sequenced manner.
In another aspect, a system for cleaning ventilation equipment in commercial kitchens includes a tank containing a supply of heated wash liquid, the tank including at least one outlet for transmitting heated wash liquid to a plurality of output lines. Each output line includes an associated flow control device for controlling a flow of heated wash liquid thereto, each output line connected for carrying heated wash liquid to a respective ventilation equipment cleaning station. A plurality of return lines carry wash liquid back from the ventilation equipment cleaning stations after the wash liquid has been delivered thereto so as to recirculate the wash liquid back to the tank for re-use. A controller is operable during a washing cycle to effect operation of the flow control devices such that wash liquid is delivered to the ventilation equipment cleaning stations in a sequenced manner.
A further aspect provides a method for controlling delivery of a recirculated wash liquid to a plurality of ventilation equipment cleaning stations. The method involves (a) providing a plurality of output lines, each output line leading to a respective ventilation equipment cleaning station; (b) providing a plurality of pressure operated valves, each pressure operated valve positioned for controlling flow of wash liquid to a respective output line; (c) providing a source of pressurized liquid; (d) providing a plurality of pilot lines, each pilot line positioned between the source of pressurized liquid and a control input of a respective pressure operated valve; wherein the pilot lines are placed in fluid communication with the pressurized fluid manifold to open the pressure operated valves, and wherein the pilot lines are taken out of fluid communication with the pressurized fluid manifold to close the pressure operates valves.
In yet another aspect, a system for maintaining a supply of heated wash liquid which is repeatedly used for cleaning ventilation equipment includes a tank for containing a supply of heated wash liquid and a temperature sensor for monitoring a temperature of the supply of wash liquid. A heating unit separate from the tank is provided. A heating unit input line delivers wash liquid from the tank to the heating unit and a heating unit output line delivers wash liquid from the heating unit back to the tank. A pump causes wash liquid to flow from the tank, through the heating unit input line, through the heating unit, through the heating unit output line, and back to the tank, wherein wash liquid is heated as it passes through the heating unit. A controller receives an output of the temperature sensor, controls the pump, and controls the heating unit. The controller may be operable to control the heating unit and the pump so as to maintain the temperature of the supply of wash liquid at or above a threshold temperature.